Pollution Research Paper

ROAD TRAFFIC CONGESTION AND VEHICULAR EMISSIONS IN ENUGU URBAN NIGERIA

EZE C.T., UGWOKE J.L. AND UGWOKE J.J.

Abstract

The study was aimed at assessing road traffic congestion and vehicular emissions in Enugu Urban, Nigeria with a view of identifying factors that influence them and evolve suitable mitigation measures. The study area included three major and two minor roads in Enugu Urban. The three major roads represented the experimental study routes and included Ogbete, Abakpa-Nike and Kenyatta roads while the two minor roads represented the control study routes and had Abakiliki and Ugwuaji roads. Traffic congestion was measured through the estimation of vehicular density, mean speed and cordon count. Questionnaires were administered to commercial motorists and environmental professionals using systematic and purposive sampling techniques respectively to study traffic related characteristics. Traffic monitoring was carried out in the morning (7:30am- 11:30am), afternoon (12:30pm-3:30pm) and evening (4:00pm-10:00pm) as a function of traffic density, mean speed and flow rate of vehicles while air samples were randomly collected and monitored in the morning (8:30am-10:30am) and evening (4:30pm -6:30pm) for the presence and varying concentrations of carbon monoxide (CO), nitrogen dioxides (NO2) and sulphur dioxides (SO2) with the aid of 350XL Emission Analyzer. Data collection was done in three (3) different days of a week (Monday, Wednesday and Friday) and twice monthly during September – November 2017. The findings of this study showed that the experimental study locations experienced high traffic congestion at the peak periods of 7.00am – 9.00am and 5.00pm-7.30pm except Ogbete road, which experienced perennial traffic congestion. The average speed of vehicles in the experimental routes was 0.016km/h - 0.022km/h during peak period as against the approved speed limit of 60- 80km/h on normal road condition. The concentration of vehicular emissions as obtained in the experimental routes is significantly different (P<0.05) from the control routes and also differs significantly (P<0.05) from WHO permissible limits for Air quality. The study recorded significant relationships between traffic congestion and the incidence of vehicular emissions in the study area. The finding of this study suggests that major roads within the Enugu metropolis may not be safe from traffic related pollution threats. There is an urgent need to focus on air quality management in urban areas to safeguard the environment and public health. The study recommends the provision of required road facilities, enforcement of traffic control laws by relevant authorities and good transportation management system in the study area.